Radio buttons - howto disable callback on deselect?

[Daniel Pekelharing <legendstar gmail com>]

Hi all,

Is there anyway to disable a radio button/menu-item calling the callback
function when it gets "deselected"?

In other words when the user selects an option, only call the callback
for the newly selected radio item and not for the previously selected
one (which is deselected)...

Thanks in advance!
-- 
Daniel Pekelharing
<legendstar gmail com>